rtmp-services: Only do URL check for Facebook

Prevents services with special exception services from unintentionally
using the wrong server.  There's no real reason to be doing this on
anything but Facebook at the moment anyway.

plugins/rtmp-services/rtmp-common.c

@@ -36,7 +36,7 @@ static void ensure_valid_url(struct rtmp_common *service, json_t *json,
 
 	if (!service->server || !servers || !json_is_array(servers))
 		return;
-	if (astrcmpi(service->server, "auto") == 0)
+	if (astrstri(service->service, "Facebook") == NULL)
 		return;
 
 	json_array_foreach (servers, index, server) {